vm86old • man page

vm86old, vm86 - enter virtual 8086 mode

vm86old • man page

vm86old, vm86 - enter virtual 8086 mode

vm86old (2)

Leading comments

Copyright 1993 Rickard E. Faith (faith@cs.unc.edu)
Copyright 1997 Andries E. Brouwer (aeb@cwi.nl)
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(The comments found at the beginning of the groff file "man2/vm86old.2".)

NAME

vm86old, vm86 - enter virtual 8086 mode

SYNOPSIS

DESCRIPTION

The system call
vm86()
was introduced in Linux 0.97p2.
In Linux 2.1.15 and 2.0.28, it was renamed to
vm86old(),
and a new
vm86()
was introduced.
The definition of
struct vm86_struct
was changed
in 1.1.8 and 1.1.9.

These calls cause the process to enter VM86 mode (virtual-8086 in Intel
literature), and are used by
dosemu.

VM86 mode is an emulation of real mode within a protected mode task.

RETURN VALUE

On success, zero is returned.
On error, -1 is returned, and
errno
is set appropriately.

ERRORS

EFAULT

This return value is specific to i386 and indicates a problem with getting
user-space data.

ENOSYS

This return value indicates the call is not implemented on the present
architecture.

EPERM

Saved kernel stack exists.
(This is a kernel sanity check; the saved
stack should exist only within vm86 mode itself.)

CONFORMING TO

This call is specific to Linux on 32-bit Intel processors,
and should not be used in programs intended to be portable.

COLOPHON

This page is part of release 4.13 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
www.kernel.org/doc/man-pages